Cigarette making machines

ABSTRACT

A cigarette making machine with a suction conveyor includes a cover which extends along the conveyor to define a cover space along and adjacent to the outer surface of the filler stream, and includes openings, such as ports or slots, for permitting air to flow under the influence of the suction through the cover space to entrain particles of tobacco which become separated from the filler stream.

United States Patent 11 1 1111 3,850,177 Labbe 1451 Nov. 26, 1974 [54] CIGARETTE MAKING MACHINES 3,059,650 10/1962 Gamberini 131/84 B X 3,091,244 5/1963 Molins et al. 131/84 C [75] Inventor- P -P 3,094,127 6/1963 Gamberini 131/84 B x Neullly-suf-seme, France 3,125,099 3/1964 Labbe 131/84 B 3,244,184 4/1966 Petru 131/84 C [73] Asslgnee' Mom's London England 3,348,551 10/1967 Pinkham 131/84 c [22] Filed: Oct. 19, 1971 3,495,599 2 1970 MOllIiS 131 110 x 211 App] 190,549 FOREIGN PATENTS OR APPLICATIONS 1,009,664 11/1965 Great Britain 131/84 C Foreign Application Priority Data Prima'y Examiner joseph S Reich Oct. 20, 1970 Great Britain 49843/ Attorney Agent, or Firm craig & Antoneui [52] US. Cl. ..131/66,131/84 B, 131/84 C I [51] Int. Cl. A24c 05/18 T T [58] Field of Search n 131/84 R 84 B 84 C A cigarette making machme with a suct1on conveyor 131/21 b includes a cover which extends along the conveyor to define a cover space along and adjacent to the outer [56] References/Cited surface of the filler stream, and includes openings, such as ports or slots, for permitting air to flow under UNITED STATES PATENTS the influence of the suction through the cover space to 1,879,016 9/1932 Austin 131/84 B UX entrain particles of tobacco which become separated ilgggleng 131/110 x from the finer Stream 3,030,966 4/1962 Lanore 131/84 0 13 Claims, 12 Drawing Figures SHEET 2 OF 4 PATE NTE HUVZGISH CIGARETTE MAKING MACHINES This invention is concerned especially with machines ing other similar articles for smoking. The term tobacco will be used with the intention that it should be regarded as including any material or mixture of materials which may be used to form the filler of a cigarette or other similar article for smoking.

A machine according to one aspect of the present invention includes a port in a wall of the channel, near the band, through which air is drawn by a supercharger fan to increase the air velocity through the channel and towards the band. This supercharger fan is also connected to a suction space adjacent to the outer surface of the fully formed tobacco stream (i.e., downstream of the channel) to maintain a suction pressure in the space substantially the same as or greater than the suction pressure in the channel at the end adjacent to the band.

The use of a supercharger fan is shown in itself from US. Pat. No. 3,019,793. However, with reference to FIG. 2 of that patent, it will be seen that the space to the left of the end wall of the channel 12 is at atmospheric pressure; a flap seal 64 prevents the flow of air from the atmosphere into the channel, i.e. in the direction opposite to the direction in which the tobacco stream is conveyed by the band 20. In accordance with the present invention, the space to the left of the end wall 15 and adjacent to the fully formed tobacco stream is substantially enclosed and is maintained at a suction pressure which is preferably at least as great as the suction pressure in the top left-hand corner of the channel 12, so that there is no need for a seal such as the seal 64.

In a preferred machine according to this invention there is a trimmer, for example like the trimmer 60 shown in US. Pat. No. 3,019,793, which removes part of the tobacco stream and is also enclosed in the suction space. The discard tobacco removed by the trimmer is carried away pneumatically in a duct through which air is drawn by the supercharger fan.

According to another aspect of this invention, a cigarette making machine includes a conveyor which carries a cigarette filler stream by means of suction towards a rod-forming device by which the tiller stream is enclosed in a wrapper to form a continuous cigarette rod, characterised in that the machine includes a cover which extends along the conveyor to define a cover space along and adjacent to the outer surface of the filler stream, and includes means for permitting or producing an air flow through the cover space in which particles of tobacco which become separated from the filler stream are entrained.

Examples of machines according to this invention are shown in the accompanying drawings. In these drawings:

FIG. 1 is a diagrammatic longitudinal sectional view of the filler stream forming part of the machine;

FIG. 2 is an enlarged section through the tobacco stream, taken on the line IIII in FIG. 1;

FIG. 3 is a diagrammatic view similar to FIG. 1 of another machine;

FIG. 4 is a section on the line IVIV in FIG. 3;

FIG. 5 is a section on the line V-V in FIG. 3;

FIG. 6 is a view similar to FIG. 3, but showing a different machine;

FIG.7 is a section on the line VIIVII in FIG. 6;

FIG. 8 is a view bascially similar to that shown in FIG. 3, of another machine with additional details;

FIG. 9 is an enlarged section on the line lX-IX in FIG. 8;

FIG. 10 is an enlarged section on the line XX in FIG. 8;

FIG. 11 is a still further enlarged section on the line XIXI in FIG. 8; and

FIG. 12 is an enlarged fragmentary plan view in the direction of the arrow XII in FIG. 11.

The machine shown in FIG. 1 includes a vertical channel 10 up which tobacco particles are carried by air towards a porous band 12 against which the tobacco particles form a cigarette filler stream 14. Suction in a suction box 16 above the band holds this fillter stream against the bottom surface of the band so that the stream is carried by the band towards a rod-forming section of the machine by which the stream is enclosed in a continuous paper web 18. Before it reaches the rod-forming section, part of the stream is removed by a trimmer 20.

The air flow up the channel 10 is produced mainly by a supercharger fan 22 of which the inlet is connected by a line 24 to a louvred port 26 in one side wall of the channel 10, as described in US. Pat. No. 3,019,793.

To the left of the channel 10, and adjacent to the tobacco stream 14, there is a suction space 28 defined partly by bottom wall sections 30, 32 and 34. Air is drawn continuously from the space 28 through a pipe 36 by the action of the supercharger fan 22, as noted below. In the preferred arrangement shown, the air flowing through the pipe 36 also carries away the discard tobacco thrown down by the trimmer 20. Accordingly the pipe 36 leads in fact to a cyclone 38 which has a tangential outlet 40 through which the discard tobacco is discharged, and an axial air outlet 42 which is connected to the inlet of the fan 22. The outlet 40 has an air seal, for example formed by a paddle wheel.

Air can flow into the suction space 28 from the atmosphere through vents (not shown) which are such that the suction pressure in the space 28 is slightly greater than the suction pressure in the top end of the channel 10. Accordingly there is a slight air flow from the channel 10 to the space 28, as shown by the arrow 44. The vents into the space 28 may for example be holes or slots. For example, there may be holes at intervals along the wall section 34 and in the side walls in the region of the bottom wall section 30. In addition, or as an alternative, there may be slots in both of the side walls defining the space 28, extending all the way along the space (and possibly as far as the left-hand end of the wall section 34), just below the bottom surface of the tobacco stream.

Rails 46 and 48, which form extensions of the side walls enclosing the suction space 28, have inclined bottom edges 46A and 48A. Air flows inwards through slots below these edges, as shown by the arrows, the slots being defined by the edges 46A and 48A and by a paper shield 50 which extends above the paper 18 until the point where the suction above the band 12 is released so as to deposit the tobacco stream 14 on the paper. The slots below the edges 46A and 48A may, for example, be of approximately 1 mm. width.

The side walls defining the suction space 28 may include air inlet slots forming extensions of the slots below the edges 46A and 48A of the rails, as shown in FIG. 2.

As an example, the suction pressure in the suction box 16 above the band 12 may be 500 mm. of water gauge. This suction in the region above the channel produces an upward air flow through the channel, but this upward air flow may be increased by between 40 and 150 percent by means of the supercharger fan. The supercharger fan may for example be designed to produce a large air flow at a low pressure head. For example, the suction pressure at the inlet of the supercharger fan may be approximately 75 mm. of water gauge. The

suction pressure inside the channel 10 at its upper end, may be approximately 63 mm., and the suction pressure in the space 28 may be about 63 mm. or slightly higher.

The discard tobacco discharged from the cyclone 38 may be returned to the main body of tobacco, for example in the hopper of the machine, upstream of the point at which the tobacco is projected into the channel 10.

The machine shown in FIG. 3 is similar to that shown in FIG. 1 in that tobacco is showered upwards by means of air through a shower channel 52 to build up a cigarette filler stream on a pervious band 54, most of the air being drawn through the channel 52 by means of a supercharger fan (not shown) connected to a louvre port 56 in one wall of the channel. However, the band carries the filler stream initially away from the continuous wrapper web 58, round a pulley 60, past a trimmer 62 and then partly round a pulley 64 to a point at which a transfer wheel 66 receives the filler stream and carries it by means of suction on to the web 58. The general arrangement is in accordance with an invention described in US. Pat. No. 3,750,678.

As'shown in FIG. 4, the channel 52 is formed mainly by front and back walls 52A and 52B. Adjacent to the band 54 there are front and back rails 68 and 70 which have inner walls 68A and 70A defining a narrow trough of uniform width and depth, and recessed parts 68B and 708 which form a deepening extension to the trough, but with an increasing width. The tobacco showered through the channel 52 builds up to form a cigarette filler stream 72 which is held on the band 54 by suction (for example 500 mm. water gauge) applied through the band from a suction chamber 74.

During use of the amount of tobacco showered through the channel 52 is normally such as to just till the narrow trough formed between the walls 68A and 70A of the rails, as shown in FIG. 4. Any momentary excess in the tobacco delivery rate results in a filler stream which projects significantly out of the narrow trough. Immediately downstream of the channel 52 (in relation to movement of the hand) there is a cover 76 which defines with the recessed parts 688 and 70B of the rails a cover space 78 through which air is drawn from the channel 52 as a result of the suction pressure in the cover space (for example about 70 to 75 mm.

water gauge) being greater than the suction pressure in the channel in the region of the band (for example about 60 to 65 mm. water gauge). The cover space 78 is of a relatively small cross-section until the band reaches the pulley 60, so as to produce a relatively fast air stream, for example about 9 to 9.5 metres/sec. In the region of the pulley 60 and further downstream the cover 76 has the shape shown in FIG. 5. Furthermore, as shown in FIG. 5, extensions of the rails 68 and in the region of the pulley 60 and further on have crosssectional shapes which no longer include the recessed parts 683 and 708 shown in FIG. 4.

In order to increase the flow of air into the cover space from the channel 52, the flow of air into the louvre port 56 near the downstream end wall 52A of the channel 52 is reduced as a result of the louvre port terminating along an oblique boundary 56A, so that more of the air flowing up the channel near the end wall 52A passes the louvre port and reaches the upper end of the channel, thus tending to continue into the cover space; this effect is promoted by the fact that the entry to the cover space is formed by a curved corner 53.

Centrifugal force helps to ensure that any excess tobacco carried forward through the cover space 78 by the air moving into the cover space remains separate from the main body of the tiller stream carried by the band. When this excess tobacco reaches the top run 78A of the cover space, it may settle back on the main body of the tiller stream. Alternatively, the air flow may be fast enough to carry some or all of the tobacco all the way to a box 82 containing the trimmer 62, so that the excess tobacco can be carried away, for example by means of suction through a discard pipe 83, together with the discard tobacco removed by the trimmer.

A further possibility is that the excess tobacco may fly off through a pipe shown dotted in FIG. 3.

The suction pressure in the cover space 78 may be determined partly by the suction pressure in the pipe 83 and partly by the suction applied through the band from the suction chamber 74. Slots 84 between the cover 76 and the rails 68 and 70 at regular intervals are of dimensions such as to let in the necessary volume of air at various positions along the cover space.

FIG. 6 shows 'a machine which is generally similar to that shown in FIG. 3, except'that the channel 52 and the band assembly have been rotated through approximately so that the band is in an upright position. The parts shown in FIG. 6 have the same reference numerals as equivalent parts in FIG. 3 but with the addition of a prime. A discard pipe 83' is shown for remov ing the discard tobacco which is separted from the main body of the filler stream by the trimmer 62. The excess tobacco carried through the cover space 78' by air is also removed through the pipe 83'. For this purpose the discard tobacco removed by the trimmer falls into a trough 86 formed at the bottom of the box 82' housing the trimmer. At one end of the trough there is a venturi-shaped opening to atmosphere through which air enters as a high-speed jet to carry the discard tobacco and excess tobacco through the trough and straight into the pipe 83, which at its inlet end forms an extension to the trough.

It should be noted that as the cover space 78 extends downwards from the pulley 60' to the box 82' (and is even inclined so that the cover is slightly below the tiller stream on the band) gravity does not tend to return the excess tobacco to the main body of the tiller stream on the band. However, if it is desired to return the excess tobacco to the main body of tobacco, this can be done by fitting the cover 76 with an internal deflector or series of deflectors to deflect any tobacco moving in the cover space towards the main body of tobacco, so that the excess tobacco (or at least some of it) can again be held with the main body of the tobacco by suction applied through the band.

The cross-sectional shape of the cover 76' in the region around the pulley 60' and further on is the same as that shown at 78 in FIG. 5. Thus, as the crosssectional area of the cover space 78' is larger in this region than it is immediately downstream of the shower channel, the air speed is reduced and may be equal to or less than the speed of the band which may, for example, move at about 280 metres per minute or at a somewhat higher speed.

The machine shown in FIG. 8 is basically similar to that shown in FIG. 3 in that it includes a channel through which tobacco is showered upwards by means of air produced partly by a supercharger fan connected to a louvre port (not shown) similar to the louvre port 56 in FIG. 3. Thus a cigarette filler stream 91 (FIGS. 9-11) is formed on a band 92 which moves around two pulleys (as in FIG. 3) and delivers the cigarette filler stream to a suction transfer wheel 94 which in turn carries the filler stream on to a continuous wrapper web 96. Before the filler stream reaches the wheel 94, it is trimmed by a trimmer comprising cooperating discs 98 and a rotary brush 100 mounted in a housing 102. A discard pipe 104 connected to a source of suction draws away the discard tobacco removed by the trimmer, together with any tobacco which becomes separated from the main body of the cigarette filler stream and is conveyed to the housing 102 through a cover space 106 in the manner described with reference to FIGS. 3 to 5.

FIG. corresponds generally to FIG. 5 and shows the band 92 passing around a pulley 108 which runs between fixed walls 110 and 112 of a suction chamber 114. The pulley comprises spaced walls 108A and 1088 so that suction from the suction chamber is applied through the band 92 to hold the filler stream 91 on the band in the region of the pulley.

The sides of the filler stream '91 in the region of the pulley are confined by rails 116 and 118 which are secured to a rigid cover section 120 by bolts 122 which are screwed into the rails and pass through slots 124 in the cover to enable the lateral positions of the rails to be adjusted; that is to say, to change the width of the filler stream. Lateral movement of the rails (once the bolts 122 have been loosened) is achieved by means of screws 126 and 128 which engage with side flanges 130 and 132 on the cover. Each rail has screws of the type 126 alternating at regular intervals with screws of the type 128. Each screw 126 passes through a clearance hole in the corresponding flange 130 and is screwed into the corresponding rail 116, so that tightening the screws 126 pulls the corresponding rail outwards; on the other hand, each screw 128 is screwed through the corresponding flange 132 and has its inner end abutting against the rail 1 18, so that tightening of the screws 128 results in the corresponding rail 118 being pushed inwards. The bolts 122 are aligned with the screws 128.

FIG. 10 further shows that the walls 110 and 112 of the suction chamber have, in the region of the pulley 108, air inlet passages 134 through which air is drawn in by the suction in the suction chamber, so that cleaning air flows inwards along both the inner and outer faces of the edge portions of the band 92 to clear away any particles between the band and the pulley or rails.

There are holes or slots A at intervals along the cover section 120 to let in the necessary volume of air at various positions along the cover space.

The semi-circular cover section 120 which extends round the pulley 108 is mounted at its upper end of a pivot 136, so that the cover section 120 can be swung in a counterclockwise direction, as seen in FIG. 8, about the pivot 136 to carry the rails away from the band. The purpose of this will be described further on. During normal use, the cover section 120 is secured in position by a releasable fastener 138.

After passing round the pulley 108, the filler stream 91 is confined between straight rails 140 and 142 which are carried by a straight cover section 144 which, like the cover section 120, is of relatively thick crosssection so as to be rigid enough to carry the rails, and has air inlet holes or slots 144A. The rails 140 and 142 are secured to the cover section 144 by means of bolts 146 in the manner described with reference to FIG. 10, and there are again adjusting screws 148 for adjusting the width of the filler stream. Along the straight upper run of the band 92, the edge portions of the band are each supported by low-friction inserts 150 mounted in an upper wall 152 of the suction chamber. Each rail is spaced from the wall 152 by the thin heads 154A of studs 154 situated at regular intervals along the wall 152, so that cleaning air can flow inwards between the rails and the wall 152 and above and below the band, for the purpose already mentioned.

The cover section 144 has connected to it a number of side members 156 which are pivoted by means of pins 158 to parts 160 secured to the wall 1 10 of the suction chamber. Thus the cover portion 144, carrying with it the rails, can be swungabout the axis of the pivots 160 in an anti-clockwise direction (FIG. 9) to expose the band 92. While the machine is running, the cover is locked in the position shown by eccentric discs 162 engaging behind fixed members 164. Each eccentric disc 162 is carried eccentrically by a spindle 166 which can be rotated manually by means of a lever 168 to a position in which the disc 162 can disengage with the member 164 when the band is required to be exposed.

A further curved cover section 169 (FIG. 8) carries rails extending from the downstream end of the rails 140, 142 to the point at which the filler stream is transferred to the wheel 94. The cover section 169 can be swung in a clockwise direction (FIG. 8) about a pivot 173 to allow access to the band. In the immediate vicinity of the transfer point there is a hinged door 175 which can be opened to allow ready access to the tiller stream in the region of the transfer point.

Across the top of the channel 90 (along the bottom run of the band 92) there are rails 170 and 172 (FIG. 11). The inner surfaces of these rails include parallel parts 170A and 172A defining a narrow trough, and flat recessed parts 1708 and 172B defining a progressively widening extension to the trough into which-excess tobacco protrudes momentarily (or possibly continuously). For a short distance downstream of the channel 90, (Le, between the channel and the curved cover section 120) the cover space 106 is defined by the surfaces 1703 and 172B of the rails and a cover section 174; the inner surface of the cover section 174, where it is furthest from the band, is at the same distance from the band 92 as the inner surface of-the cover part 120 at the point where it is furthest from the band 92.

The top of the channel 90 is formed by front and back walls 90A and 908 which at their upper extremities are slightly below the bottom surfaces of the rails 170 and 172, thus defining a clearance to allow movement of the rails relative to the walls 90A and 908. Light tubes 176 and 178 form seals between the walls and the rails, being held in position as a result of the suction pressure within the channel; rods or wires 180A and 182 extend through the tubes and have their ends fixed so as to prevent the tubes from falling out of position when the machine is not running.

Towards the downstream ends of the walls 90A and 90B (for example along about the last 40 percent) there are grooves 185 which extend obliquely forwards in the direction of motion of the band 92, the direction of movement of the band being shown by the arrow 187 in FIG. 12. More specifically, the grooves are inclined to the band by the angle A which is equal to 30. Thus, as a result of the suction pressure within the channel, air is drawn in from the atmosphere through the grooves 185. This air flows partly along the surfaces 1703 and 1728 of the rails and assists the movement of the last part of the tobacco shower into the trough between the rails, while at the same time giving the air flow a forward component so as to increase the velocity of the air flowing into the cover space 106 from the channel.

As shown in FIG. 11, the band 91 runs along lowfriction inserts 180 and 182 set in the walls 1 l and 1 12 of the suction chamber (here shown somewhat diagrammatically). Between the walls 1 l0 and 112 and the rails there are sl0ts;184 at regular intervals along both sides of the band to let in cleaning air, asdescribed above. r

The rails 170 and 172 are each carried by two parts 186 (see FIG. 8) which are pivotally connected to parts 188 fixed to the side walls of the suction chamber; this enables each rail to be swung outwards to allow access to the band. Furthermore, each rail can be adjusted as to its lateral position so as to vary the width of the trough formed between the rails.

Suction is supplied to the suction chamber 114 through a pipe 190 (FIG. 8), and the suction chamber is arranged by suitable means so that it can be made to slide in the direction of the axis of the pipe 190, being carried by the pipe 190. When the band 92 needs to be changed, the suction chamber, together with the rails and the various cover sections, is moved far enough along the axis of the pipe 190 to be clear of the trimmer discs 98. Then the band is exposed by swinging the top rails to one side (as already described), swinging the cover sections 169 and 120 away from the band, and swinging the rails I70 and 172 respectively sideways.

Other small parts can then be disconnected to completely expose the band, which can then be removed and replaced by a new band. After that the various parts are moved back into position, and the suction chamber is moved along the axis of the pipe, back to its operative position.

The following provision is made for tensioning the band 92. The pulley 108 is mounted for rotation in a holder consisting of front and back walls 192A and 1928 (FIG. 10). This holder fits within the walls 110 and 112 of the suction chamber and is pivoted with respect to the suction chamber by a pivot pin 194 (FIG. 8). Thus by means of a spring or other tensioning device, the pulley 108 can be swung in a counterclockwise direction about the pin 194 to tension the band.

I claim:

1. A cigarette making machine comprising an elongated air-pervious conveyor, a channel extending towards the conveyor for directing tobacco towards the conveyor to form a cigarette filler stream on the conveyor, and suction means substantially coextensive with the operative length of the conveyor for compressing the filler stream thereon and for drawing air through the channel and towards the conveyor, characterized in that the machine includes a cover which extends along the conveyor to define a cover space extending from the channel and along and adjacent to the surface of the filler stream opposite to the conveyor, which space is under suction as a result of the transmission of suction through the conveyor from the said suction means, and including means for producing an air flow from the channel and into and through the cover space, moving substantially parallel to and in the same direction as the conveyor, which air flow entrains any particles of tobacco which become separated from the tiller stream.

2. A cigarette making machine according to claim 1, including a trimmer for trimming away part of the filler stream, and in which the air flow through the cover space carries the separated particles of tobacco towards the trimmer, where the particles are removed together with discard tobacco trimmed ofi by the trimdischarged, means for connecting said discard pipe to a source of suction, the ,air flow through the cover space being at least partly the result of the suction applied through the discard pipe.

4. A cigarette making machine according to claim 1, including rails extending along opposite sides of the conveyor and having mutually opposed parallel surfaces normal to the surface of the conveyor defining a relatively narrow trough deep enough to contain substantially all the tobacco which is normally directed onto the conveyor, the rails having also recessed parts forming in cross-section a wider extension to the trough to receive any momentary excess of tobacco, and at least part of any such excess being carried forward, at

, a speed greater than the conveyor, by the air flow in the veyor to assist the movement of tobacco into the trough.

7. A cigarette making machine according to claim 1, in which the conveyor is an air-pervious band which carries the filler stream by means of suction round a pulley, said pulley including means for effecting communication between said suction means and the portion of the band passing round said pulley with the filler stream lying on the outer surface of the band as it passes round the pulley, any tobacco thrown off by centrifugal force in the region of the pulley being carried forward by the air flow in the cover space, which cover space extends round the pulley.

8. A cigarette making machine according to claim 1, in which the cross-sectional area of the cover space along a section adjacent to the channel is smaller than the cross-sectional area of those sections thereof that are located downstream from said section adjacent to the channel.

9. A cigarette making machine according to claim 1 wherein said channel is defined by walls, means providing a port through one wall thereof, and suction means connected with the port means whereby at least a part of the air stream through the channel is produced thereby.

10. A cigarette making machine according to claim 9 in which the port means is elongated and has opposite ends the end of the port means adjacent to the cover space being shaped so as to promote the flow of air into the cover space.

11. A cigarette making machine according to claim 1, in which the channel is inclined to the band in the sense such that the direction of movement of the air and tobacco through the channel has a component in the direction of movement of the band.

12. A cigarette making machine according to claim 1, including a suction conveyor located at the discharge end of the band for receiving the tiller stream thereon, means for feeding and conveying a continuous wrapper web adjacent the discharge end of the suction conveyor, said web being adapted to receive the filler stream from the suction conveyor, and means for wrapping the web around the filler stream to form a continuous cigarette rod, the suction conveyor serving also to seal the adjacent end of the cover space.

13. A cigarette making machine according to claim 1, including means defining apertures for letting air into the cover space at various positions along the cover space.

UNITED STATES PATENT OFFICE- CERTIFICATE OF CORRECTION Patent No. 177 fl r d November 26, 1974 Inventor(s) Francis A.M. Labbe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Priority data incomplete. Should read:

--Oct 20,-1970 Great Britain 498.43/70 July 28, 1971 Great Britain 35513/71-- mlcd this Signed and [SEAL] Arrest:

Tenth Day of August 1976' 

1. A cigarette making machine comprising an elongated airpervious conveyor, a channel extending towards the conveyor for directing tobacco towards the conveyor to form a cigarette filler stream on the conveyor, and suction means substantially coextensive with the operative length of the conveyor for compressing the filler stream thereon and for drawing air through the channel and towards the conveyor, characterized in that the machine includes a cover which extends along the conveyor to define a cover space extending from the channel and along and adjacent to the surface of the filler stream opposite to the conveyor, which space is under suction as a result of the transmission of suction through the conveyor from the said suction means, and including means for producing an air flow from the channel and into and through the cover space, moving substantially parallel to and in the same direction as the conveyor, which air flow entrains any particles of tobacco which become separated from the filler stream.
 2. A cigarette making machine according to claim 1, including a trimmer for trimming away part of the filler stream, and in which the air flow through the cover space carries the separated particles of tobacco towards the trimmer, where the particles are removed together with discard tobacco trimmed off by the trimmer.
 3. A cigarette making machine according to claim 2, and including a discard pipe through which the separated particles of tobacco and the discard tobacco are discharged, means for connecting said discard pipe to a source of suction, the air flow through the cover space being at least partly the result of the suction applied through the discard pipe.
 4. A cigarette making machine according to claim 1, including rails extending along opposite sides of the conveyor and having mutually opposed parallel surfaces normal to the surface of the conveyor defining a relatively narrow trough deep enough to contain substantially all the tobacco which is normally directed onto the conveyor, the rails having also recessed parts forming in cross-section a wider extension to the trough to receive any momentary excess of tobacco, and at least part of any such excess being carried forward, at a speed greater than the conveyor, by the air flow in the cover space.
 5. A cigarette making machine according to claim 4 including at least in the region of the downstream end of the channel where the last tobacco is directed on to the conveyor, means defining air inlets through which air streams enter with a component of motion in the direction of movement of the conveyor.
 6. A cigarette making machine according to claim 5 in which the air inlet means are arranged to give the air streams a component of motion also towards the conveyor to assist the movement of tobacco into the trough.
 7. A cigarette making machine according to claim 1, in which the conveyor is an air-pervious band which carries the filler stream by means of suction round a pulley, said pulley including means for effecting communication between said suction means and the portion of the band passing round said pulley with the filler stream lying on the outer surface of the band as it passes round the pulley, any tobacco thrown off by centrifugal force in the region of the pulley being carried forward by the air flow in the cover space, which cover space extends round the pulley.
 8. A cigarette making machine according to claim 1, in which the cross-sectional area of the cover space along a section adjacent to the channel is smaller than the cross-sectional area of those sections thereof that are located downstream from said section adjacent to the channel.
 9. A cigarette making machine according to claim 1, wherein said channel is defined by walls, means providing a port through one wall thereof, and suction means connected with the port means whereby at least a part of the air stream through the channel is produced thereby.
 10. A cigarette making machine according to claim 9 in which the port means is elongated and has opposite ends the end of the port means adjacent to the cover space being shaped so as to promote the flow of air into the cover space.
 11. A cigarette making machine according to claim 1, in which the channel is inclined to the band in the sense such that the direction of movement of the air and tobacco through the channel has a component in the direction of movement of the band.
 12. A cigarette making machine according to claim 1, including a suction conveyor located at the discharge end of the band for receiving the filler stream thereon, means for feeding and conveying a continuous wrapper web adjacent the discharge end of the suction conveyor, said web being adapted to receive the filler stream from the suction conveyor, and means for wrapping the web around the filler stream to form a continuous cigarette rod, the suction conveyor serving also to seal the adjacent end of the cover space.
 13. A cigarette making machine according to claim 1, including means defining apertures for letting air into the cover space at various positions along the cover space. 